Preheat a large frying pan or griddle to medium heat.
If your potatoes are cold from the fridge, I recommend warming them up slightly and giving them a second mash or beating them with an electric mixer so they're easier to work with.
In a large bowl, add the mashed potatoes, eggs, flour, cheese, parsley, salt, and pepper.
Stir the ingredients together.
Grease the frying pan/skillet lightly.
Form the dough into patties, about 1/4 cup of batter each. Flatten the patty between your palms.
Fry on one side until golden (about 3-5 minutes), then flip and fry on the second side until golden.